Method of detecting gases



E. P. S. NEWMAN.

METHOD OF DETECTING GASES.

APPLlCATlON FILED DEC. 6. 1919.

1 9,65 9 Patented June 13, 1922.

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EDWIN P. S. NEWMAN, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIG-NOR TO NEWTON D. BAKER. SECRETARY OF WAR, TRUSTEE.

METHOD OF DETECTING GASES.

Specification of Letters Patent. Patented June 13, 1922.

Application filed December 6, 1919. Serial-No. 343,140.

(J'ILED UNDER THE ACT OF MARCH 3, 1883, 22 STAT. L., 6 25.)

To all whom it my concern:

Be it known that I, EDWIN P. S. NEWMAN,

a citizen of the United States, stationed at Washington, D. C.', have invented an Im provement in Method of Detecting Gases, of which the following is a specification.

- The invention described herein may be used by the Government or any of its oflicers or employees in prosecution of work for the Government, or by any other person in the United States without payment of any royalty thereon.

This invention relates to a method and means for detecting gases, and has special reference to the detection of toxic and poisonous gases in the atmospheric air.

Among the objects of this invention is the provision of a method and means for ascertaining whether or not the air in'a given locality is laden with poisonous gases or vapors; to provide a means which is sensitive, reliable, compact, portable, durable, cheap, simple, not easily disarranged or rendered ineffective by shocks or disturbances in the vicinity thereof and which will give a ready and reliable report to a person at a distance from a given locality when the atmosphere in that given locality contains the tox1c gases.

This invention has special adaptation for use in gas warfare, and since the device p-- erates upon mechanical principles rather than chemical, it is adaptable for the detection of the presence of substantially any foreign gas in the air.

Reference is to be had to the accompanying drawing which illustrates a specific modification of the apparatus forming part of this invention.

Fig.' 1 shows in a diagrammatic way the apparatus placed near the bottom of a trench for detection of gases therein.

Fig. 2 is a side elevation of the part of my apparatus comprising the casing containing the pressure diaphragm and the vertical tube in communication with said diaphragm.

Fig. 3 is a view, partly in section, showing the interior mechanism of the casing containing the pressure diaphragm.

Fig. 4 is a section along 15118311116 44 of ig. 5 is a section along the line 5-5 of Fig. g. I I

The apparatus consists of the casing 1 having perforated portions 2, 2, the interior of said casing being in communication with a long vertical conduit or tube 3, which has at its upper portion a flexible diaphragm 0 4, preferably of rubber and witha small opening 5 1n the center. thereof. A cap'6 fits over the upper portion of tube 3, and this cap is sages 7 these passages and the central openng 5 affording communication between the interior of tube 3 and the atmosphere. A valve 8 is provided within the tube 3 for cutting off communication of the interior portlon of the casing 1 with the outside atmosphere.

The casing 1 contains a plurality of diaphragms 9, 9 and the middle of said diaphragms are connected by the knobs 10 to an elongated lever 11, terminating in a rack 12. The teeth of the. rack 12 mesh with those of the pinion 13 and movement'of the lever 11 is transmitted through the rack 12, pinion 13 an gear 14 to gear 15 .mounted on shaft 16. Thegear 14 has'asector 17 thereof made of conducting material, which is electrically connected sulating material. conducting material and is electrically con-. nected to .terminal 19. When the gears 14 and 15 revolve andthe portion 17 comes in contact with gear 15, electrical communication is established between the terminals 18 and 19; when, however, the insulated section of the gear 14 meshes with the gear15, there is no electrical communication between the terminals 18 and 19.

The terminals 18 and 19 are the conductors 20, 21, and 22 to a battery 23 and electric bell 24, and when electrical connection is established between the terminals 18 and 19 through the gear 15 and sector 17, the bell 24 will ring.

In Fig. 1 there is shown the pressure device 1 placed near the bottom of a trench where 1t is suspected that the atmosphere with, gas wgrfare is as follows. -The presprovided with small tubular pas connected by sure device is placed near the bottom of the trench, as shown in Fig. 1, and the elongated. tube extends almost to the top of the trench. The poisonous gases, being heavier than the air, stay close to the ground, and this device gives satisfactory results for the detection of these gases when the top of the. tube 3 is six feet or more above the pressure device. The pressure within the casing 1 is substantially equal to that of the atmosphere at the top of the tube 3, wherein substantially pure air enters. If the air should become foul or contain poisonous gases, the latter, owing to their greater weight, will gravitate to'the bottom of the trench. The toxic gases will be in concentrated form near the bottom of the trench and will exert an increased pressure. In the upper strata of atmosphere the toxic gases will be very much diluted and at about six feet from the bottom of the trench these gases will be so rare that atmospheric pressure at such point will be substantially that of pure air, but

will differ from the pressure at the bottom of the trench sufliciently to operate the pressure diaphragm 9.

The perforated portion 2 of the casing permits air which may contain poisonous gases to exert its pressure upon the diaphragm. Whenever there is poisonous gas within the vicinity of the pressure device 1, the difference in pressure between the atmospheric air on the inside of the casing 1 and that mixed with the poisonous gas on the outside will cause the diaphragm 9 to be moved inwardly and this will cause the lever arm 11 to move, thereby bringing the conducting sector of the gear 14 in contact with the gear 15, thereby establishing electrical communication between the terminals 18 and 19- which will close the electric circuit and cause the bell 24to ring and give notice of the presence of the poisonous gas. Ordinarily the insulated portion of the gear 14 is in contact with the gear 15 and there is no electrical communication between the terminals 18 and 19, the electric circuit being open.

The function of the cap 6 is to keep awayair containing the gas from the inside of the casing 1, and sincethe heavier gases naturally seek a lower level, only lighter air will enter through the passages 7 into the interior of the casing 1. v

The present invention is not limited to the and where the higher concentrations of the gas to be detected are free to occur and the other side of said diaphragm to the pressure of the atmosphere from a higher elevation and where lower, negligible or no concentrations of the gas to be detected are likely to occur and then observing the movement of. said diaphragm.

2. A method of detecting gases comprising exposing one side of a diaphragm to pressure of a column of atmospheric air open to the surrounding air at a higher elevation than said diaphragm, the other side of said diaphragm being exposed, at the place where the presence of gas is to be detected, to pressure of the atmosphere or of the gas, and observing the movement of said diaphragm.

3. In a method of detecting gases, simultaneously exposing one side of a pressure diaphragm to the pressure of the atmosphere in the immediate vicinity of said diaphragm and where the higher concentrations of the gas to be detected are free to occur and the other side of said diaphragm to the pressure of the atmosphere from a higher elevation and where lower, negligible or no concentrations of the gas to be detected are likely to occur and transmitting motion of said diaphragm to a signaling device.

4:. In a method of detecting gases, comprising exposing one side of a diaphragm to pressure of a column of atmospheric air open to the surrounding air at a higher'elevation than said diaphragm, the other side of said diaphragm being exposed, .at the place where the presence of gas is to be detected, to pressure of the atmosphere or of the gas and transmitting motion of said diaphragm to a signalin device.

EDWIN P. S. NEWMAN. 

